Sagittarius

One of the first items on almost any amateur astronomer’s “to-do” list is completing the Messier marathon — looking at all 110 objects cataloged by Charles Messier. Messier himself began the first marathon 250 years ago.

If you judge by the layout of the night sky, you might think that centaurs roamed across every field and mountain in ancient Greece. That’s because these mythological beasts are represented by not one, but two constellations created by the Greeks.